微细电解铣槽加工技术研究

发布时间：2018-01-20 02:29

本文关键词： 微细电解加工微型槽纳秒脉冲电源双喷嘴对流式电解液流场加工精度　出处：《大连理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：近年以来,随着先进制造技术的迅猛发展,微型零部件结构越来越广泛地应用于航空航天、生物医疗以及微机电系统(MEMS)等领域。微细电解加工技术作为微细特种加工技术之一,相比于其他微细加工技术,微细电化学加工是以离子形式进行材料去除,且加工表面质量高,无再铸层,加工工具电极无损耗,工具电极与工件不接触,无加工应力和加工热等优点,成为先进制造技术中的关键技术之一。微型槽结构作为微型结构中的基本结构单元,是涡喷式航空发动机涡轮叶片散热单元的核心结构,对其要求极其苛刻,要求具有耐高温高压,表面质量高且无再铸层,微型槽几何成型精度高等特性。本文基于微细电解加工技术,设计研制了实验室首台微细电解加工机床,基于此研制机床进行微细电解加工型槽结构进行深入研究和探索实验,并对实验结果进行分析讨论,主要从以下方面进行研究。研制实验室首台Micro ECM机床,并基于Lab VIEW平台开发机床在线控制系统。通过优化控制程序和调节机床主轴PID参数,使其运动控制系统响应时间小于0.1ms,最大超调量小于0.1μm,可实现工具电极在线制备、加工信号在线监测以及可读取CNC数控加工代码执行三维加工指令等功能,满足微细电解加工要求。本文针对微细电解铣槽加工技术中的加工参数对微型槽加工结果的影响进行探索研究实验。通过改变加工电源频率、脉宽、加工电压、工具电极转速以及电解液浓度等不同加工参数设计五组实验,加工出19组微型槽阵列,实验结果表明,采用低压高频窄脉宽加工电源结合工具电极高速旋转能够在保证加工材料去除效率的同时显著提高微细电解铣槽加工成型精度和表面质量,其加工底面表面粗糙度为80nm。针对上述实验过程中出现的微型槽左右侧壁与底面拐角曲率半径以及左右侧壁斜度偏差较大等问题,本文基于流体力学伯努利原理建立了双喷嘴对流式电解液流场模型,并设计2组对比实验进行实验验证其模型的可行性。实验结果表明,采用双喷嘴对流式电解液流场的微细电解铣槽加工能够有效均化加工区域电解液流场和电场,提高微型槽加工几何精度的一致性。其加工后微型槽结构左右侧壁拐角曲率半径平均偏差从3.66μm降低至0.34gm,其侧壁与底面拐角曲率半径值控制在8μm；微型槽结构左右侧壁斜度平均偏差从4.37°减小至0.73°,侧壁斜度几乎接近垂直,仅为91°。
[Abstract]:In recent years, with the rapid development of advanced manufacturing technology, the structure of micro-parts is more and more widely used in aerospace. Micro Electrochemical Machining (ECM) is one of the special micro machining technologies, compared with other micro machining technologies, such as biomedicine and micro electromechanical systems (MEMS). Micro-electrochemical machining is to remove materials in the form of ions, and the surface quality is high, there is no re-cast layer, tool electrode has no loss, tool electrode is not in contact with workpiece, no processing stress and processing heat, and so on. As the basic structure unit of micro structure, micro slot structure is the core structure of turbine blade heat dissipation unit of turbojet aero-engine. It is required to have the characteristics of high temperature and high pressure, high surface quality and no recast layer, high precision of geometric forming of micro groove. Based on the technology of micro electrolysis machining, the first micro electrolytic machining machine tool in laboratory has been designed and developed in this paper. On the basis of this machine tool, the structure of micro-electrolysis machining groove was studied and the experimental results were analyzed and discussed. The first Micro ECM machine tool is developed from the following aspects. The on-line control system of machine tool is developed based on Lab VIEW platform. The response time of the motion control system is less than 0.1ms by optimizing the control program and adjusting the PID parameters of the spindle of the machine tool. The maximum overshoot is less than 0.1 渭 m, which can realize the functions of on-line preparation of tool electrode, on-line monitoring of machining signal and reading of CNC NC machining code to execute 3D machining instructions. In order to meet the requirements of micro electrolytic machining, this paper studies the effect of machining parameters on the machining results of micro electrolytic milling groove. By changing the frequency of power supply, pulse width, processing voltage. Five groups of experiments were designed with different machining parameters, such as rotating speed of tool electrode and concentration of electrolyte, and 19 groups of microgroove arrays were fabricated. The experimental results show that. The high speed rotation of low voltage high frequency narrow pulse width machining power supply and tool electrode can improve the machining precision and surface quality of micro electrolytic milling groove while ensuring the material removal efficiency. The roughness of the machining bottom surface is 80 nm. In view of the problems such as the corner curvature radius of the left and right side wall of the micro groove and the corner curvature radius of the left and right side wall and the deviation of the left and right side wall slope which appear in the above experiment process. Based on the Bernoulli principle of fluid mechanics, a two-nozzle flow field model for electrolytic electrolyte was established in this paper, and two groups of experiments were designed to verify the feasibility of the model. The flow field and electric field of electrolyte in the area can be effectively homogenized by micro-electrolytic milling groove machining with double nozzles to the flow field of flow electrolyte. The geometric accuracy of micro grooves is improved. After machining, the mean deviation of curvature radius of left and right side walls of micro grooves is reduced from 3.66 渭 m to 0.34 gm. The curvature radius of the side wall and bottom surface is controlled at 8 渭 m. The mean deviation of the left and right side slope of the micro groove structure is reduced from 4.37 掳to 0.73 掳, and the lateral wall slope is almost vertical, only 91 掳.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG662

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